package cn.picclife.mwx.common.core.util.crypto;

import java.io.IOException;
import java.security.SecureRandom;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.xerces.impl.dv.util.Base64;


/**
 * 
* @ClassName: DESUtils 
* @Description: TODO(DES加密 解密算法) 
* @author jun.hai 
* @date 2015-3-17 下午02:45:52
*
 */
public class DESUtils {

	private final static String DES = "DES";
    private final static String ENCODE = "UTF-8";
 //   private final static String defaultKey = "picclife";
    private static final Log log = LogFactory.getLog(DESUtils.class);
 /*   public static void main(String[] args) throws Exception {
        String data = "GS-9My7HrFvjs0-iX2MbkLfFSO7wtzaDH1bxLOoDzvdUa9p45L3-C9z_fJvkdgTS1aEeFPrkNW-xmMgCgQifpZBhlTNPxIZNKZt1khYGkNo-xIIPlIo84qsqnrmiCnVgEIHjAIAXBA";
        String key = "aY4aM7JnOyOkz51lUzYNYObQqa0dY5l2osdBhsuWy7YYKXlRxJkZRRad";
        
        String result = encrypt(data, key);
        log.info("加密后："+result);
        
        log.info("解密后："+decrypt(result, key));
    }*/

    /**
     * 使用 默认key 加密
     * 
     * @return String
     * @author jun.hai
     * @date 2015-3-17 下午02:46:43
     */
/*    public static String encrypt(String data) throws Exception {
        byte[] bt = encrypt(data.getBytes(ENCODE), defaultKey.getBytes(ENCODE));
        String strs = Base64.encode(bt);
        return strs;
    }*/

    /**
     * 使用 默认key 解密
     * 
     * @return String
     * @author jun.hai
     * @date 2015-3-17 下午02:49:52
     */
/*    public static String decrypt(String data) throws IOException, Exception {
        if (data == null)
            return null;
        byte[] buf = Base64.decode(data);
        byte[] bt = decrypt(buf, defaultKey.getBytes(ENCODE));
        return new String(bt, ENCODE);
    }
*/
    /**
     * Description 根据键值进行加密
     * 
     * @param data
     * @param key 加密键byte数组
     * @return
     * @throws Exception
     */
    public static String encrypt(String data, String key) throws Exception {
        byte[] bt = encrypt(data.getBytes(ENCODE), key.getBytes(ENCODE));
        String strs = Base64.encode(bt);
        return strs;
    }

    /**
     * Description 根据键值进行解密
     * 
     * @param data
     * @param key 加密键byte数组
     * @return
     * @throws IOException
     * @throws Exception
     */
    public static String decrypt(String data, String key) throws  Exception {
        if (data == null)
            return null;
        
        byte[] buf = Base64.decode(data);
        byte[] bt = decrypt(buf, key.getBytes(ENCODE));
        return new String(bt, ENCODE);
    }

    /**
     * Description 根据键值进行加密
     * 
     * @param data
     * @param key 加密键byte数组
     * @return
     * @throws Exception
     */
    private static byte[] encrypt(byte[] data, byte[] key) throws Exception {
        // 生成一个可信任的随机数源
        SecureRandom sr = new SecureRandom();

        // 从原始密钥数据创建DESKeySpec对象
        DESKeySpec dks = new DESKeySpec(key);

        // 创建一个密钥工厂，然后用它把DESKeySpec转换成SecretKey对象
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);
        SecretKey securekey = keyFactory.generateSecret(dks);

        // Cipher对象实际完成加密操作
        Cipher cipher = Cipher.getInstance(DES);

        // 用密钥初始化Cipher对象
        cipher.init(Cipher.ENCRYPT_MODE, securekey, sr);

        return cipher.doFinal(data);
    }

    /**
     * Description 根据键值进行解密
     * 
     * @param data
     * @param key 加密键byte数组
     * @return
     * @throws Exception
     */
    private static byte[] decrypt(byte[] data, byte[] key) throws Exception {
        // 生成一个可信任的随机数源
        SecureRandom sr = new SecureRandom();

        // 从原始密钥数据创建DESKeySpec对象
        DESKeySpec dks = new DESKeySpec(key);

        // 创建一个密钥工厂，然后用它把DESKeySpec转换成SecretKey对象
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);
        SecretKey securekey = keyFactory.generateSecret(dks);

        // Cipher对象实际完成解密操作
        Cipher cipher = Cipher.getInstance(DES);

        // 用密钥初始化Cipher对象
        cipher.init(Cipher.DECRYPT_MODE, securekey, sr);

        return cipher.doFinal(data);
    }

}
